Waveguides are used to transport electromagnetic radiation from one location to another. For frequencies ranging from 1 to 100 GHz and above (RF, microwave, and millimeter), waveguides are typically constructed of metal enclosures that form a hollow cavity or series of cavities. Electromagnetic radiation is introduced at one or more locations in the cavity system, and extracted at other locations. A simple embodiment of this is a rectangular tube that can transport radiation along the length of the tube, from one end to the other.
For some applications, a waveguide may be made from dielectric material, such as polymer or ceramic. This can have the benefit of providing improved structural integrity for the waveguide, may allow a change of effective impedance for the waveguide, and may enable improved transport of electromagnetic radiation at certain frequencies. Electromagnetic radiation may be contained in the dielectric by total internal reflection at the dielectric/air boundary.
For some applications, waveguides may contain a variety of materials within them to accomplish certain effects, such as filtering, attenuation, coupling or modulation of the electromagnetic wave. Waveguides may include electrically conductive materials, resistive materials, ferromagnetic materials, dielectric materials, as well as gas and vacuum.
The three-dimensional shape of the cavities may be designed to produce special effects, such as filtering, attenuation, coupling, and the like. For example, cavities may be constructed to produce resonating effects that serve to filter or enhance transport of the electromagnetic wave.
A wide variety of devices have been designed and built using three-dimensional waveguides, employing numerous geometries and materials. This is well documented in the literature and understood by those skilled in the art. Many companies currently sell waveguide components intended to transport or modulate electromagnetic radiation.
In many cases there is a desire to move electromagnetic radiation from one portion of a waveguide system to another portion, then at a later time, change the system to move electromagnetic radiation to a different portion of the system. This is done using what is referred to as a waveguide switch.
A waveguide switch contains an intermediary waveguide that is used to connect two other waveguides to each other (each terminating at a port on the waveguide switch). At the desired time, a motor is engaged which moves the intermediary waveguide to connect two different ports to each other. The motor typically rotates the waveguide switch to enable connection to a different port. These waveguide switches enable dynamic control over the routing of electromagnetic radiation in a waveguide system.
Conventional waveguide switches are quite large and bulky, employing a large motor to rotate a machined metal structure 90 degrees. At the starting location, the switch connects two ports to each other. After a rotation of 90 degrees, the switch connects two different ports together. This operation is slow and only permits a limited number of routing configurations.
It is desirable to provide a low cost, small, switching system that can quickly change routing from one waveguide to another, allowing a wide variety of routing configurations.